[4] It is an advanced derivative of the former Alenia Aeronautica's earlier G.222 (C-27A Spartan in U.S. service), equipped with the engines and various other systems also used on the larger Lockheed Martin C-130J Super Hercules.

In addition to the standard transport configuration, specialized variants of the C-27J have been developed for maritime patrol, search and rescue, C3 ISR (command, control, communications, intelligence, surveillance and reconnaissance), fire support/ground-attack and electronic warfare missions.

In 2007, the C-27J was selected as the Joint Cargo Aircraft (JCA) for the United States military; these were produced in an international teaming arrangement under which L-3 Communications served as the prime contractor.

The C-27J has also been ordered by the military air units of Azerbaijan, Australia, Bulgaria, Chad, Greece, Italy, Kenya, Lithuania, Mexico, Morocco, Peru, Romania, Slovakia, Slovenia, and Zambia.

[6] Other changes include a fully digital MIL-STD-1553 systems and avionics architecture, and an updated cargo compartment for increased commonality.

[14] In 2006, LMATTS was dissolved when Lockheed Martin offered the C-130J in 2006 as a contender in the same U.S. Army and U.S. Air Force Joint Cargo Aircraft (JCA) competition in which the C-27J was competing.

[17] GMAS bid the C-27J in the JCA competition against Raytheon and EADS North America's C-295 to replace existing Short C-23 Sherpa, Beechcraft C-12 Huron and Fairchild C-26 Metroliners in the Army National Guard, and as a substitute tactical airlifter for Air National Guard groups or wings losing C-130s to retirement or Base Realignment and Closures.

[18][19] By November 2006, the C-27J completed the U.S. Department of Defense's Early User Survey evaluations, having flown a total of 26 hours and surpassed all requirements.

[20] The JCA's final selection was expected in March 2007, however it was postponed until 13 June 2007, when the Pentagon announced the award of a US$2.04 billion contract for 78 C-27Js, including training and support, to GMAS.

[25] As of 2020[update], orders stand at Australia (10), Bulgaria (3), Chad (2), Greece (8), Italy (12), Kenya (3), Lithuania (3), Mexico (4), Morocco (4), Peru (4), Romania (7), Slovakia (2), Zambia (2), United States (21), and an undisclosed country (2).

[26][27][28][29][30][31][32][33][5] In November 2020, Leonardo launched the C-27J Next Generation programme with new equipment, systems and aerodynamic solutions to improve operating efficiency and enhance performance.

[41] On 26 January 2012, the Department of Defense announced plans to retire all 38 USAF C-27Js on order because of excess intra-theater airlift capacity and budgetary pressures;[42] the C-130 would perform its functions.

[44] On 23 March 2012, the USAF announced the C-27J's retirement in fiscal year 2013 after determining other programs' budgetary needs and requirement changes for a new Pacific strategy.

[53] In July 2013, the United States Coast Guard considered acquiring up to 14 of the 21 retired C-27Js and converting them for search-and-rescue missions, while cancelling undelivered orders for the HC-144 Ocean Sentry to save $500–$800 million.

[61][62][63] From 12 September 2008 to 27 January 2009, a pair of Italian Air Force C-27Js were deployed to Afghanistan to contribute to NATO in-theatre airlift operations.

[75] In December 2011, the Royal Australian Air Force (RAAF) issued a Foreign Military Sales request for 10 C-27Js valued at US$950m to replace its retired DHC-4 Caribou fleet.

[76][77] Australia had opted for the C-27J over the rival EADS CASA C-295 following a RAAF evaluation, which had noted the C-27J's wider and taller cabin being compatible with the Australian Army's general purpose G-Wagen vehicle,[78] and palletized goods.

[86] In June 2013, the Peruvian Air Force was negotiating to acquire four C-27Js for $200 million; future purchases by Peru may increase the total to 12 Spartans.

[96] In 2010, the Indian Air Force issued a Request for Information (RFI) for 16 medium military transport aircraft; Alenia Aeronautica responded with data on the C-27J.

Other proposed variants of the platform include a multi-mission C-27J that could be armed with various air-launched weapons and equipped with a maritime surveillance radar; Alenia Aermacchi have promoted this model to the Royal Air Force.

[103] Alenia Aermacchi bid up to 32 aircraft with lifetime maintenance from KF Aerospace and in-service support from General Dynamics Canada.

In 2008, US$32 million was reallocated to buy a C-27J for the U.S. Air Force Special Operations Command, to fulfill requirements defined by AFSOC for the AC-XX concept, a replacement for the aging Lockheed AC-130s.

The AC-27J was to be a multi-mission platform, equipped with full-motion cameras and outfitted to support covert infiltration and other ground operations, armed with either a 30-millimeter or 40-millimeter gun or precision-guided munitions such as the Viper Strike bomb.

14 USCG C-27Js are to be rebuilt as HC-27Js for maritime patrol, surveillance, medium-range search and rescue, drug and migrant interdiction, and disaster response missions.

[123] In October 2020, the annual Documento Programmatico Pluriennale (DPP) 2020-2022 of Italian Minister of Defence indicates realization of the MC-27J to support special operations.

One publicised ability of the aircraft is the disruption of radio communications and, in particular, remote detonators commonly used on improvised explosive devices (IEDs).